Jag XKR-S GT vs SRT Viper TA

542bhp Brit brawls with 631bhp of American muscle. But which will come out on top?

Already a rare piece of exotica, the most exclusive bit of the Viper TA is its TA Orange paint. Ninety-three will be available in this colour, with 33 each in Venom Black or Bright White. All of the other bits that go into turning a regular SRT Viper into a TA are available in the configurator - you just need to know which ones to pick.

So, for the record, these are the key items: Sidewinder II wheels - 14kg lighter a set than standard; 355mm-wide Pirelli P Zero Corsa tyres - which generate the biggest contact patch of any production car on sale today; solid front and rear anti-roll bars - 30 per cent stiffer than standad; two-piece Brembo brakes - lighter and with a bigger braking surface; two-stage Bilstein dampers - with Race and Road modes; and also an aero package that increases downforce at 150mph by 700 per cent. (The V10 engine stays in standard 631bhp form.)Much simpler to just buy the TA, but if they've run out, those are the bits you need to add. Because they turn the Viper into the car it always wanted to be.